CMOS integrated pixel array for low-level radiation detection using ‘time compression’ parametric amplification

In this work, theoretical modeling and simulations of a ‘time compression’ parametric amplification pixel array to be used in CMOS imaging for low-level or near IR radiation are presented. The implementation in the higher resistivity substrate process used for smart-power devices, namely the 30 V thin-film 1.0 μm SIMOX-CMOS based on Silicon-on-Insulator technology, enables isolated separation of photoactive and readout circuitry areas when integrated on the same chip. The method presented shows that very high readout current peaks can be generated which are much higher than the mean value of the photocurrent induced. Thus, the parametrically amplified readout signals can be detected by a low-noise peak-detector circuit. The 500×500 μm2 area pixels with internal parametrically controllable amplification and increased pixel fill-in factor (>90%) present higher detection volume due to enlarged deep-depletion region depth caused by a low resistivity substrate. Moreover, the X–Y addressing and the inverse exponential dependence of the parametric amplification on the incoming radiant flux for each pixel provide separately controllable single-pixel internal amplification which improves the intra-scene high dynamic range demands.